<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <script>
        var socket;
        if(window.WebSocket){
            socket = new WebSocket("ws://localhost:7000/hello");
            //相当于channelRead0，服务端回送消息
            socket.onmessage = function (ev) {
                var rt = document.getElementById('responseText');
                rt.value = rt.value + "\n" + ev.data;
            }
            socket.onopen = function (ev) {
                var rt = document.getElementById('responseText');
                rt.value = rt.value + "\n" + "连接开启了...";
            }
            socket.onclose = function (ev) {
                var rt = document.getElementById('responseText');
                rt.value = rt.value + "\n" + "连接关闭了...";
            }
        }
        function send(message) {
            if(!window.socket){
                return;//判断websocket对象是否已经创建好
            }
            if(socket.readyState == WebSocket.OPEN){
                socket.send(message);
            }else{
                alert("连接没有开启")
            }
        }
    </script>
    <form onsubmit="return false">
        <textarea name="message" style="height: 300px;width: 300px"></textarea>
        <input type="button" value="发送消息" onclick="send(this.form.message.value)">
        <textarea id="responseText" style="height: 300px;width: 300px"></textarea>
        <input type="button" value="清空内容" onclick="document.getElementById('responseText').value = ''">
    </form>
</body>
</html>